Clamp



FIG. 1 shows a perspective view of my design for a clamp;

FIG. 2 is a front end view thereof;

FIG. 3 is a rear end view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is an opposite side view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a top view thereof.

The broken line showing of a turn screw in FIG. 3 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a clamp, as shown and described. 